Recordable disk media, such as a magneto-optical disk or the like, can be accessed randomly with ease as compared with a tape-shaped recording medium, such as a DAT (Digital Audio Tape), a compact cassette tape or the like. Therefore, data need not be recorded from the inner peripheral side to the outer peripheral side of the disk in the correct order of a first track to an nth track. In other words, even when a piece of music is recorded on the disk at its physical random positions, if recorded address data of music recorded from the first to nth tracks are managed, then it is possible to reproduce music in the correct order.
Further, a track serving to record a piece of music need not always be recorded on consecutive segments (segment is referred to as a portion in which physically continuous data is recorded) and may be discretely divided into a plurality of segments and recorded on the disk.
In particular, in the system in which data read out from a magneto-optical disk is temporarily stored in a buffer memory at high transfer rate, read out from the buffer memory at a constant transfer rate and demodulated as an audio reproduced signal, even when reading of data from the magneto-optical disk is temporarily interrupted due to access between the segments, it is possible to continuously output the reproduced audio signal.
Accordingly, if recording and reproducing operation within the segment and high speed access operation, i.e., access operation which is ended within a reproducible time based on a data stored amount generated by a difference between a write data and a read rate of the buffer memory are repeated continuously, even when a track of a piece of music is physically divided into a plurality of segments, music can be recorded/reproduced satisfactorily.
As shown in FIG. 1, for example, although a first music is recorded as a segment M.sub.1 and a second music is recorded as a segment M.sub.2 continuously, it is possible to record fourth and fifth music separately on the disk as shown by segments M.sub.4(1) to M.sub.4(4) and M.sub.5(1) to M.sub.5(2). FIG. 1 is a schematic diagram and, in actual practice, it is frequently observed that one segment is recorded over several to several 100s of tracks or greater.
When music is recorded on and erased from the magneto-optical disk repeatedly, irregular empty regions occur on the track due to a difference between a playing time of recorded music and a playing time of erased music. However, if a discrete recording is executed as shown in FIG. 1, then it becomes possible to record music of which playing time is longer than that of the erased music by effectively using the erased portion. Therefore, it is possible to solve a problem of useless data recording area generated by repetitive recording/erasure. Incidently, recorded data is not limited to "music" and any kinds of audio signals may be recorded. In this specification, let it be assumed that music is recorded as data (tracks of continuous one unit.
Upon recording, a recording is made on this disk while accessing segments forming a plurality of non-recording regions. Upon reproduction, segments should be accessed such that a piece of music is reproduced correctly. To this end, segments of a piece of music, such as data connecting M.sub.4(1) to M.sub.4(4) and data indicative of the non-recording region are held as U-TOC (user TOC, hereinafter simply referred to as U-TOC) which is rewritten at each recording or erasing operation. Under the control, the recording/reproducing apparatus reads this U-TOC information and allows the head to access the tracks so as to perform proper recording/reproducing operation.
As described above, the disk is provided with the U-TOC in order to manage the address of the first to nth tracks and the non-recording regions and to manage the connection of segments in respective tracks and the non-recording region. In the system for checking this information, the recording/reproducing apparatus can easily execute edit, such as division and connection of tracks, by rewriting the U-TOC.
When the divide operation is carried out at the position of somewhere of the first music, for example, if the U-TOC is rewritten such that the address position is set to the end address of the first music and that the position of the end address of the first music from that position is managed as start address and end address of a resulting second music, then the original first music is divided into the first and second music at the position of somewhere of the first music.
When the combine operation is carried out at the boundary position of the first and second music, if the U-TOC is rewritten such that the start address of the first music and the end address of the second music are managed as start address and end address of a new first music, then the original first and second music are combined to provide a new first music.
In order to carry out the above-mentioned edit, the conventional disk recording and reproducing apparatus is provided with edit mode operation function in addition to the reproducing mode (operation mode, such as playback, playback pause, fast forward, fast rewind and access) and the recording mode (operation mode, such as recording and recording pause).
FIG. 2 shows an operation processing in the edit mode.
In a playback mode (F900), for example, if an edit key is operated (F901.fwdarw.YES), then operation in the edit mode is selected. If combine, divide and erase (function to rewrite U-TOC so as to erase a designated track) are entered and title input (processing for rewriting character data, such as music name and disk name corresponding to a designated track or disk on the U-TOC) is carried out as edit function, it is determined in steps F902, F903, F904 and F905 whether or not any processing is selected. Then, a combine processing (F906), a divide processing (F907), an erase processing (F908) and a title enter processing (F909) are executed.
However, even when the edit modes are prepared so that various kinds of edit processing and U-TOC edit processing can be carried out as described above, there is then the problem that it is not so easy for the user to use the edit function. In particular, the combine processing and the divide processing are not so easy to use.
In the divide processing in which a track number is incremented, for example, the divide processing should preferably be carried out by the user at any time in the recording or playback. Specifically, if the divide processing is carried out to input a track mark when a speaker is changed during contents of conference are recorded, the divide processing need not be carried out after the recording was ended and a desired speech can be readily accessed and played back upon reproduction. Similarly, when a radio broadcasting is recorded, if a track mark is immediately input with ease at the completion of music, then it is convenient for the user to access and reproduce the music upon playback. Further, it is convenient for the user if the user inputs a track mark to an arbitrary point during the playback while listening to reproduced music or if the user carries out the combine processing by using the track mark.
However, these processing are executed in the edit mode as described above and cannot be carried out with ease during the recording and playback.
In view of the aforesaid problem, according to the present invention, it becomes possible to execute the divide processing and the combine processing with ease.